– 1 ½ cups White granulated sugar – ½ cup Powdered sugar – 3 Large egg – 1 Egg yolk – ½ cup Unsalted butter melted – ½ cup Oil – 1 teaspoon Pure vanilla extract – 1 cup All-purpose flour – 1 cup Unsweetened cocoa powder – 1 tablespoon Cornstarch – 1 teaspoon Salt – 1 cup Semi-sweet chocolate chip – 1 ¾ cups All-purpose flour – ½ teaspoon Cornstarch – 1 teaspoon Salt – ¾ cup Unsalted butter room temperature – ¼ cup White granulated sugar – ¼ cup Brown sugar packed light or dark – 1 teaspoon Pure vanilla extract – ⅓ cup Milk – 1 cup Mini chocolate chip
Pre-heat the oven to 350℉. Use baking nonstick spray on a 9x9-inch square pan. Place parchment paper on the pan's bottom and sides. Spray again.
1
Mix flour, cocoa powder, cornstarch, and salt in a medium basin. Set aside.Beat sugar, powdered sugar, eggs, and egg yolk on high speed for 2 minutes in a mixer with a whisk attachment.
2
Mix in melted butter, oil, and vanilla. Combine.Mix in dry ingredients. Low-speed mix until mixed. Mix in chocolate chips just until incorporated.
3
Pour brownie batter in pan. Spread evenly. Bake 40–45 minutes. Bake until a toothpick reveals moist crumbs.Remove brownies from pan when they've cooled fully.
4
Preheat oven to 300℉. Flour a cookie sheet. Bake 5 minutes, cool completely.Mix butter, brown sugar, and sugar on high for 2 minutes. Add milk and vanilla. Mix medium-speed.
5
Add flour, cornstarch, and salt. Low-speed mix until mixed. Mix in small chocolate chips.Use an offset spatula to cover the cooled brownies with cookie dough. Cut 16 squares.
6